TY - JOUR
T1 - The nepheline aegirine pegmatite of Cnoc na Sroine
JF - Transactions of the Edinburgh Geological Society
JO - Transactions of the Edinburgh Geological Society
SP - 273
LP - 273
M3 - 10.1144/transed.8.2.273
VL - 8
IS - 2
AU - Goodchild, J.G.
Y1 - 1903/01/01
UR - http://trned.lyellcollection.org/content/8/2/273.abstract
N2 - Mr Goodchild exhibited part of a remarkable boulder found in the east side of Cnoc na Sroine in Sutherlandshire. The true nature of all the minerals composing it was not understood until a specimen of it had been examined by Mr Teall, who recognised it as an Orthoclase-Nepheline-Ægirine Pegmatite, very similar in many of its characteristics to some pegmatites which occur in Scandinavia. Both the Nepheline and the Ægirine occur in it as large crystals. The latter mineral is, however, devoid of crystalline terminations; though it is in every part of the specimen idiomorphic in the prismatic zone. This furnishes one of many examples of elongated crystals in which the ends have been either hindered in their growth by the pressure arising from the extension of the minerals contiguous to them, or else their terminations have been absorbed in the process of consolidation. The rock is supposed to have been formed in close contiguity to some calcareous stratum. At the time when the specimen was exhibited, the parent rock had not been found in situ. The specimen shown on this occasion has since been cut, and parts of it sent to London. The remaining portions are exhibited, each under their respective headings as minerals, in the Scottish Mineral Collection in the Edinburgh Museum of Science and Art, and in the Rock Collection in the same Museum, as part of the Collections of the Geological Survey.
ER -